TW201800913A - Touch panel and manufacturing method thereof - Google Patents

Abstract

The invention discloses a touch panel and a manufacturing method thereof. Different from a method of printing a black matrix on a cover glass by monolithic printing and then abutting the cover glass with a touch sensing structure, a method of using a yellow light lithography process is provided to replace the method, a black matrix photoresist is used to directly make a shading layer on the touch sensing structure, to cover a conductive circuit of a frame region. Then concave positions of the shading layer, exposed out of a sensing region are filled by a filling layer, and height of the filling layer is flushed with height of the shading layer. The touch panel can prevent fitting bubbles generated by printing segment difference, defects on appearance of the panel are reduced. Since the yellow light lithography process can make thickness of the shading layer reduce, touch efficacy is improved. the touch panel can be matched with multi-layout design, and capacity is greatly improved.

Description

Touch panel and manufacturing method thereof

The invention relates to a touch panel and a manufacturing method thereof, and particularly to a touch panel and a manufacturing method thereof capable of improving a black matrix printing step difference.

Thanks to the advancement of science and technology, people can see portable electronic devices everywhere in life, such as laptops, tablets, smart phones, etc., and as the user's degree of dependence increases, the functions of portable electronic devices also It is becoming more and more powerful; the common feature of these products is that they have a display screen, and can display a variety of multimedia videos to users. Furthermore, in recent years, the trend of portable electronic devices is to provide larger screen touch operations, making consumers more convenient and flexible in operation.

Generally speaking, touch screens can be divided into resistive touch screens and capacitive touch screens. Resistive touch screens are generated between the glass and the electrode due to the pressure applied by the user's touched position. The capacitive touch screen is sensed by the position of the user's touch because the capacitance of the electrode changes due to the touch. At present, the design of capacitive touch panels is mainly divided into film-type and glass-type touch panels, which usually include protective glass (Cover Glass or Cover Lens) covering the sensing electrode layer. ), The periphery of the lower surface of the protective glass is also covered with a black matrix (Black matrix, BM), wherein the sensing electrode layer is used to detect the touch position, and conductive lines are provided around the sensing electrode layer, and the black matrix is used immediately To shield surrounding conductive lines.

The current main method of manufacturing black matrices is to use black ink screen printing. For example, referring to FIG. 1, in the manufacturing process of the glass-type touch panel 10 of OGS or TOL, the black matrix 12 is printed on the glass substrate 11 before the touch sensing structure 13 is manufactured. In addition, as shown in FIG. 2, the black matrix 22 of the thin-film touch panel 20 is a single-sheet printing method, which is printed before the protective glass 21, and then performed with an optical adhesive (OCA) 24 and a touch sensing structure 23. fit. However, because the step difference is generated after printing, it is difficult to remove the air bubbles generated when the optical adhesive 24 is bonded, and the appearance of the panel is also prone to abnormal color difference. In addition, in the application of the new generation touch panel, this kind of single-chip printing production method is not only inefficient, but also the thickness of the black matrix formed by the printing process is relatively thick, about 10-25 microns (um), which may easily cause touch. Phenomenon of failure.

Current research also proposes solutions to this issue. For example, Taiwan Patent Bulletin No. I504983 patent, mainly for the defects of uneven coating or tiny bubbles when printing or coating the shielding layer (that is, the black matrix). Under strong light, it is easy to show small holes, which affects The appearance of the product, therefore, a non-transparent layer is set between the shielding layer and the light source below. This non-transparent layer can block the strong light from the light source below from illuminating the holes and prevent the holes from being visible to the naked eye.

However, the above-mentioned solution only covers the holes and defects, and does not directly address the structural or process problems. The actual improvement is questionable. One of the main causes of bubble defects is caused by the printing step difference. The previous case did not propose an improvement plan for this part of the issue. Even if the covering method proposed in the previous case, the printing step difference still exists, and there is still a film. Thickness is too thick and production efficiency is not good, which makes the space for improvement is quite limited. Therefore, there is an urgent need to propose a method that can effectively solve the problem of the printing step difference of the black matrix, and can fully improve the existing process or structure, and at the same time can improve the production efficiency and quality requirements.

In view of this, the present invention addresses the defects of the prior art, and its main purpose is to provide a touch panel and a manufacturing method thereof, which can effectively solve various problems such as bubble defects caused by the difference in printing segments of the black matrix.

Another object of the present invention is to provide a touch panel and a manufacturing method thereof, which can reduce the thickness of the light-shielding layer through the yellow light lithography process, and can also adopt multi-typesetting design, so that the productivity and performance can be improved simultaneously.

To achieve the above object, the present invention provides a touch device, which includes a first and a second substrate, a first and a second sensing electrode layer, a plurality of first and second conductive lines, a light shielding layer, and a filling layer. According to the stacking order, the surface of the first substrate has a sensing region and a frame region surrounding the periphery of the sensing region. The first sensing electrode layer and the first conductive circuit are disposed on the first substrate and located in the sensing region and the frame region, respectively, and the first conductive circuit is electrically connected to the first sensing electrode layer. The light-shielding layer covers the first conductive circuit and extends to the surface of the first substrate, and surrounds the sensing area to form a hollow depression. The light-shielding layer is a black matrix resist formed by exposure and development; the filling layer is filled with The flat hollow is recessed, and the height of the filling layer is flush with the light shielding layer. The second sensing electrode layer and the second conductive line are disposed below the first substrate and are located in the sensing area and the frame area, respectively. The second conductive line is electrically connected to the second sensing electrode layer, and the first conductive line is electrically connected to the first conductive line. A conductive line. The second substrate is disposed below the second sensing electrode layer and the second conductive circuit. In the present invention, there is no height difference between the light-shielding layer and the filling layer, and it can be flatly bonded with the protective glass provided later, which can effectively solve the problem of bubble defects.

In addition, the present invention also provides a method for manufacturing a touch device. The steps are to first provide a first substrate and a second substrate that are stacked on top and bottom. The surface of the first substrate has a sensing area and a surrounding area around the sensing area. In the frame region, a first sensing electrode layer and a plurality of first conductive circuits are formed on the first substrate and are located in the sensing region and the frame region, respectively. The first conductive circuit is electrically connected to the first sensing electrode layer, and the second sensing The test electrode layer and the plurality of second conductive lines are formed on the second substrate and located in the sensing area and the frame area, respectively. The second conductive line is electrically connected to the second sensing electrode layer, and the first conductive line is electrically connected to the first conductive line. Then, a black matrix resist is used to form a light-shielding layer covering the first conductive circuit and extending to the surface of the first substrate through the exposure and development processes, and forming a hollow depression surrounding the sensing area; , Forming a filling layer to fill in the hollow depressions so that the height of the filling layer is flush with the light-shielding layer.

Compared with the prior art, the present invention does not print a light-shielding layer on the protective glass, and then attaches it to the touch-sensing structure to generate a height step. Instead, it uses a yellow light lithography process to directly produce light-shielding on the touch-sensing structure. Layer to cover the conductive lines in the frame area, and then fill the gap with the filling layer. Therefore, in addition to avoiding the height difference caused by printing, avoiding the problem of lamination bubbles and reducing defects in the appearance of the panel, the invention can also reduce the thickness of the light shielding layer by using the yellow light lithography process, thereby improving the touch performance and further Combined with multi-typesetting design, the productivity can be greatly increased.

Detailed descriptions will be provided below through specific embodiments to make it easier to understand the purpose, technical content, features and effects of the present invention.

The invention discloses a touch panel and a manufacturing method thereof. The touch panel is applied to, for example, a display device, a tablet computer, a smart phone, a notebook computer, a desktop computer, a television, a satellite navigation, a car display, an aeronautical display or Various electronic devices such as portable DVD players, and touch screens can be divided into resistive touch screens and capacitive touch screens. Among them, capacitive touch panels are mainly film-type and glass-type ( Glass-type) touch panel, and the present invention mainly focuses on the structure of a thin-film touch panel, more particularly a double-layer thin-film (Glass-Flim-Flim, GFF) touch panel.

Referring to FIG. 3, a cross-sectional structure diagram of a touch panel 100 according to an embodiment of the present invention is shown.

The touch panel 100 includes a first substrate 110 and a second substrate 120. The first substrate 110 defines a sensing region 111 and a frame region 112 surrounding the periphery of the sensing region 111 to carry a first sensing electrode layer 130 and a plurality of first conductive lines 131. The test electrode layer 130 is located in the sensing region 111 on the first substrate 110, and the first conductive circuit 131 is located in the frame region 112 on the first substrate 110. The second substrate 120 is used to carry the second sensing electrode layer 140 and a plurality of second conductive lines 141. The second sensing electrode layer 140 is located on the second substrate 120 at a position corresponding to the sensing region 111 of the first substrate 110. The second conductive line 141 is located on the second substrate 120 at a position corresponding to the frame region 112 of the first substrate 110. In this embodiment, the first sensing electrode layer 130 is a transmitting (TX) electrode layer, and the second sensing electrode layer 140 is a receiving (RX) electrode layer, and is electrically connected to the first conductive line 131 and the second conductive line 141, respectively. The first conductive line 131 and the second conductive line 141 are also electrically connected.

The light-shielding layer 150 covers the frame area 112 and covers the first conductive circuit 141. Specifically, the light-shielding layer 150 extends downward from the top of the first conductive circuit 141 to the surface of the first substrate 110, and surrounds the sensor. A hollow recess is formed in the region 111, that is, the first sensing electrode layer 130 on the sensing region 111 is exposed.

The filling layer 160 covers the sensing area 111 and fills the hollow recesses of the light shielding layer 150 so that the height of the filling layer 160 can be approximately flush with the height of the light shielding layer 150.

In addition, the protective glass 170 is adhered and fixed above the light-shielding layer 150 and the filling layer 160 through the first adhesive layer 180. Since the height of the light-shielding layer 150 and the filling layer 160 is roughly flush, and no height difference is formed, the protection is performed. After the glass 170 is adhered to the light-shielding layer 150 and the filling layer 160, there will be no air bubbles in the first adhesive layer 180, which can avoid hole defects caused by the appearance of the panel.

The first substrate 110 and the second substrate 120 may be adhered and fixed by the second adhesive layer 190.

In addition, as shown in FIG. 4, a plurality of pads 121 are provided on the second substrate 120 corresponding to the frame region 112 of the first substrate 110 for external telecommunications transmission, so that some of the pads 121 are electrically conductive. The first conductive circuit 131 is connected, and the remaining pads 121 are electrically connected to the second conductive circuit 141. In particular, the present invention is not limited to a single planar wiring. In this embodiment, a plurality of through holes are opened in the first substrate 110, and a conductive through hole 113 is formed by forming a conductive material in the through holes as the first conductive The conductive medium that the circuit 131 overlaps with the second conductive circuit 141 is electrically connected to the pad 121 to achieve a double-layer overlap wiring. More preferably, the first conductive lines 131 and the second conductive lines 141 are staggered side by side, and can be evenly distributed by the first substrate 110 and the second substrate 120 located on the upper and lower layers, respectively. Each plane achieves the frame reduction and realizes the panel design requirements of narrow frames. In practical applications, the profiled substrate structure can also be used to achieve the effect of double-layer wiring shunting.

In the above embodiment, the material of the first substrate 110 and the second substrate 120 may be polyethylene terephthalate (PET) film. Of course, the material is not particularly limited, but is currently on the market The most widely used type is PET film. The first sensing electrode layer 130 and the second sensing electrode layer 230 are mainly composed of a transparent conductive material, such as indium tin oxide (ITO), indium zinc oxide (IZO), and cadmium oxide. Cadmium tin oxide (CTO), aluminum zinc oxide (AZO), indium zinc zinc oxide (ITZO), tin oxide, zinc oxide, cadmium oxide ( cadmium oxide, hafnium oxide (HfO), indium gallium zinc oxide (InGaZnO), indium gallium zinc magnesium oxide (InGaZnMgO), indium gallium magnesium oxide , InGaMgO), indium gallium aluminum oxide (InGaAlO), carbon nano tube (CNT), silver nano carbon tube or copper nano carbon tube, etc., or other transparent conductive materials and metals Or non-metallic composition. The first conductive circuit 131 and the second conductive circuit 141 may be made of the aforementioned transparent conductive material or metal, such as silver. The most common of the first adhesive layer and the second adhesive layer is Optical Clear Adhesive (OCA), which can be cured by UV light to produce an adhesive effect, and the transmittance is high (> 99%), so Suitable for bonding of this type of product. The filling layer may be formed by a transparent protective film or a transparent dry film photoresist. The above materials may be different according to actual needs, which is not limited by the present invention.

Here, the height difference between the light-shielding layer 150 and the filling layer 160 in the present invention is clearly defined. Please refer to FIG. 5, the thickness of the first lead line 131 is generally less than about 1 micrometer (μm). The thickness a is about 1.5 to 5 micrometers, and the thickness b of the filling layer 160 is about 1.5 to 5 micrometers ± 1 micrometer. Then, the thickness difference between the light shielding layer 150 and the filling layer 160, that is, the height step, is less than about 1 micrometer. In addition, an included angle c between the sidewall of the filling layer 150 and the light shielding layer 160 is about 15 to 90 °.

Next, please refer to FIGS. 6A to 6B in sequence, which is a flowchart of a manufacturing method of the touch panel provided by the present invention; meanwhile, please refer to FIGS. 7A to 7H, which are provided by the embodiments of the present invention. A cross-sectional structure diagram corresponding to each step in a method of manufacturing a touch panel. In order to clearly show the characteristics of the method of the present invention, some elements have been omitted in FIGS. 7A to 7H. If you want to know the composition of each element, please refer to the aforementioned figures 3 and 4. The production process includes the following steps:

First, referring to step S10, as shown in FIG. 7A, the aforementioned first substrate 110 is provided, and a surface of the first substrate 110 is defined with a sensing region and a border region surrounding the periphery of the sensing region. At the same time, the aforementioned second substrate is also provided (omitted from the figure)

Then, referring to step S20, the dry film photoresist is coated on the first substrate 110, and the yellow film photoresist is used to expose, develop, etch and peel the dry film photoresist to form the first sensing electrode layer 130 on the A sensing area on a substrate 110 is shown in FIG. 7B; at the same time, a position of the second sensing electrode layer on the second substrate corresponding to the sensing area of the first substrate (omitted in the figure) is formed. After that, as shown in FIG. 7C, the first conductive circuit 131 may be formed on the frame region of the first substrate 110 by coating or printing, and the first conductive circuit 131 is electrically connected to the first sensing electrode layer 130; At the same time, a second conductive line is formed on the second substrate at a position corresponding to the frame region of the first substrate, and the second conductive line is electrically connected to the second sensing electrode layer (omitted in the figure).

See step S30. Using laser drilling, a plurality of perforations are formed in the frame area of the first substrate 110, and a conductive material is plated in the perforations to form a conductive via 113. At the same time, a plurality of pads 121 are fabricated on the second substrate. 120 corresponds to the position of the border region of the first substrate 110; this portion is as shown in FIG.

See step S40. As shown in FIG. 7D, the second adhesive layer 190 is applied between the first substrate 110 and the second substrate 120, and then the two substrates are laminated and laminated by the second adhesive layer 190 At this time, the first conductive lines 131 and the second conductive lines 141 respectively located on the upper and lower layers can be overlapped through conductive vias, and are electrically connected to the pads (omitted in the figure).

Then, in step S50, the black matrix photoresist is coated on the first substrate 110, and the black matrix photoresist is exposed and developed using the yellow light lithography technology. As shown in FIG. 7E, a light-shielding layer 150 is formed to cover the first The frame region of the substrate 110 covers the first conductive circuit 131 and extends to the surface of the first substrate 110, and surrounds the sensing region to form a hollow depression to expose the sensing region of the first substrate 110.

See step S60, and then as shown in FIG. 7F, the filling layer 160 is filled in the hollow depression, so that the height of the filling layer 160 is approximately flush with the light shielding layer 150.

After that, as shown in step S70, as shown in FIG. 7G, the first adhesive layer 180 is coated on the surface of the light-shielding layer 150 and the filling layer 160, and the protective glass 170 is laminated and fixed on the first through the first adhesive layer 180. Above the substrate 110, as shown in FIG. 7H.

Subsequently, see step S80, and then perform laser cutting and polishing to obtain the structure of the GFF (Glass-Flim-Flim) thin film touch panel 100. According to the manufacturing method of this embodiment, multiple layout design can be adopted, once Making a plurality of touch panels 100 contributes to an increase in productivity.

In summary, the touch panel and its manufacturing method provided by the present invention are different from the conventional method of making a black matrix on a protective glass and then laminating it by single-sheet printing. Instead, a yellow light lithography process is used. A black matrix photoresist is used to fabricate a light-shielding layer on the touch sensing structure to cover the frame area, and then fill the recessed portion of the light-shielding layer to expose the sensing area with a filling layer, so that the height of the light-shielding layer and the filling layer are equivalent No step difference will occur. In this way, in addition to overcoming the bubble defects caused by poor printing, the invention can reduce the thickness of the light-shielding layer through the yellow light lithography process, and improve the touch performance. Furthermore, it can be used in combination with multiple layout designs to Get higher production capacity and improve industrial competitiveness.

The foregoing are merely preferred embodiments of the present invention, and are not intended to limit the scope of implementation of the present invention. Therefore, all equal changes or modifications made according to the features and spirit described in the scope of the application of the present invention shall be included in the scope of patent application of the present invention.

10‧‧‧ glass touch panel
11‧‧‧ glass substrate
12‧‧‧ Black Matrix
13‧‧‧Touch sensing structure
20‧‧‧ thin film touch panel
21‧‧‧Protection glass
22‧‧‧ Black Matrix
23‧‧‧Touch sensing structure
24‧‧‧Optical glue
100‧‧‧ touch panel
110‧‧‧first substrate
111‧‧‧Sensing area
112‧‧‧Border area
113‧‧‧ conductive via
120‧‧‧second substrate
121‧‧‧ pad
130‧‧‧first sensing electrode layer
131‧‧‧ the first conductive line
140‧‧‧second sensing electrode layer
141‧‧‧Second conductive line
150‧‧‧Light-shielding layer
160‧‧‧ Filler
170‧‧‧ protective glass
180‧‧‧first adhesive layer
190‧‧‧Second adhesive layer
a, b‧‧‧ thickness
c‧‧‧ angle

FIG. 1 is a cross-sectional structural view of a thin-film touch panel provided by the prior art. FIG. 2 is a cross-sectional structural view of a glass-type touch panel provided by the prior art. FIG. 3 is a sectional structural view of a touch panel according to an embodiment of the present invention. FIG. 4 is a schematic diagram of the overlapping method of the first substrate and the second substrate in the embodiment of the present invention. FIG. 5 is a schematic diagram of a step height difference between a light shielding layer and a filling layer according to an embodiment of the present invention. 6A and 6B are flowcharts of a method of manufacturing a touch panel according to an embodiment of the present invention. 7A to 7H are cross-sectional structural diagrams corresponding to each step in a method for manufacturing a touch panel according to an embodiment of the present invention.

100‧‧‧ touch panel

110‧‧‧first substrate

111‧‧‧Sensing area

112‧‧‧Border area

120‧‧‧second substrate

130‧‧‧first sensing electrode layer

131‧‧‧ the first conductive line

140‧‧‧second sensing electrode layer

141‧‧‧Second conductive line

150‧‧‧Light-shielding layer

160‧‧‧ Filler

170‧‧‧ protective glass

180‧‧‧first adhesive layer

190‧‧‧Second adhesive layer

Claims (15)

A touch panel includes at least: a first substrate having a sensing region on a surface thereof and a frame region surrounding the periphery of the sensing region; a first sensing electrode layer disposed on the first substrate and located on the first substrate; The sensing area; a plurality of first conductive lines disposed on the first substrate and located in the frame area and electrically connected to the first sensing electrode layer; a light shielding layer covering the first conductive lines and extending to A hollow layer is formed on the surface of the first substrate and surrounds the sensing area; a filling layer fills the hollow hole, and the height of the filling layer is flush with the light-shielding layer; a second sensing electrode layer is provided; Is located below the first substrate and is located in the sensing area; a plurality of second conductive lines are provided below the first substrate and are located in the frame area, and are electrically connected to the second sensing electrode layer, and the first conductive The lines are electrically connected to the first conductive lines; and a second substrate is disposed under the second sensing electrode layer and the second conductive lines. The touch panel according to claim 1, further comprising a first adhesive layer and a protective glass, the first adhesive layer is coated on the surface of the light shielding layer and the filling layer, and the protective glass is formed by The first adhesive layer is laminated and fixed on the light shielding layer and the filling layer. The touch panel according to claim 1, wherein the light-shielding layer is formed by a Black Matrix Resist. The touch panel according to claim 1, wherein the filling layer is formed by a transparent protective film or a transparent dry film photoresist. The touch panel according to claim 1, wherein in a direction parallel to the surface of the first substrate, the first conductive lines and the second conductive lines are interlaced side by side. The touch panel according to item 1 of the claim further includes a plurality of pads, which are disposed on the second substrate and located in the frame area, and are electrically connected to the first conductive lines and the second conductive lines, In addition, the first substrate has a plurality of conductive vias in the frame region, so that the pads are electrically connected to the first conductive lines and the second conductive lines through the conductive vias, respectively. The touch panel according to claim 1, further comprising a second adhesive layer disposed between the second substrate, the second sensing electrode layer, and the second conductive lines. The touch panel according to claim 1, wherein a thickness of the light-shielding layer is 1.5 to 5 micrometers (μm), and a thickness difference between the light-shielding layer and the filling layer is less than 1 micrometer. A method for manufacturing a touch panel includes at least the following steps: providing a first substrate and a second substrate which are stacked on top and bottom, and a surface of the first substrate has a sensing area and a periphery of the sensing area; A frame region, in which a first sensing electrode layer and a plurality of first conductive circuits are formed on the first substrate and are respectively located in the sensing region and the frame region, and the first conductive circuits are electrically connected to the first A sensing electrode layer, and a second sensing electrode layer and a plurality of second conductive lines are formed on the second substrate and are located in the sensing area and the frame area, respectively, and the second conductive lines are electrically connected to the first conductive line. Two sensing electrode layers, the first conductive lines are electrically connected to the first conductive lines; a black matrix resist is provided, and an exposure and development process is performed to form a light-shielding layer covering the first conductive lines; A conductive line extends to the surface of the first substrate and surrounds the sensing area to form a hollow depression; a filling layer is formed to fill the hollow depression, and the height of the filling layer is flush with the light-shielding layer. The method for manufacturing a touch panel according to claim 9, further comprising: coating a first adhesive layer on the surface of the light-shielding layer and the filling layer; and protecting the first adhesive layer with a first adhesive layer. The glass is laminated and fixed on the light shielding layer and the filling layer. The method for manufacturing a touch panel according to claim 9, wherein the filling layer is formed by a transparent protective film or a transparent dry film photoresist. The method for manufacturing a touch panel according to claim 9, wherein the first conductive lines and the second conductive lines are interlaced side by side in a direction parallel to the surface of the first substrate. The method for manufacturing a touch panel according to claim 9, further comprising: forming a plurality of pads on the second substrate and located in the frame area to electrically connect the first conductive lines and the second Conductive lines; and forming a plurality of conductive vias in the frame region on the first substrate for the pads to electrically connect the first conductive lines and the second conductive lines through the conductive vias, respectively. . The method for manufacturing a touch panel according to claim 9, further comprising forming a second adhesive layer between the second substrate, the second sensing electrode layer, and the second conductive lines. The method for manufacturing a touch panel according to claim 9, wherein the thickness of the light shielding layer is 1.5-5 micrometers (μm), and the thickness difference between the light shielding layer and the filling layer is less than 1 micron.